scholarly journals Assessing Vegetation Response to Multi-Scalar Drought across the Mojave, Sonoran, Chihuahuan Deserts and Apache Highlands in the Southwest United States

2021 ◽  
Vol 13 (6) ◽  
pp. 1103
Author(s):  
Pratima Khatri-Chhetri ◽  
Sean M. Hendryx ◽  
Kyle A. Hartfield ◽  
Michael A. Crimmins ◽  
Willem J. D. van Leeuwen ◽  
...  
Keyword(s):  
Climate Change ◽  
United States ◽  
Water Availability ◽  
Large Scale ◽  
Vegetation Index ◽  
Vegetation Type ◽  
Linear Trend ◽  
Severe Drought ◽  
Vegetation Productivity ◽  
Southwest United States

Understanding the patterns and relationships between vegetation productivity and climatic conditions is essential for predicting the future impacts of climate change. Climate change is altering precipitation patterns and increasing temperatures in the Southwest United States. The large-scale and long-term effects of these changes on vegetation productivity are not well understood. This study investigates the patterns and relationships between seasonal vegetation productivity, represented by Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI), and the Standardized Precipitation Evapotranspiration Index (SPEI) across the Mojave, Sonoran, and Chihuahuan Deserts and the Apache Highlands of the Southwest United States over 16 years from 2000 to 2015. To examine the spatiotemporal gradient and response of vegetation productivity to dry and wet conditions, we evaluated the linear trend of different SPEI timescales and correlations between NDVI and SPEI. We found that all four ecoregions are experiencing more frequent and severe drought conditions in recent years as measured by negative SPEI trends and severe negative SPEI values. We found that changes in NDVI were more strongly correlated with winter rather than summer water availability. Investigating correlations by vegetation type across all four ecoregions, we found that grassland and shrubland productivity were more dependent on summer water availability whereas sparse vegetation and forest productivity were more dependent on winter water availability. Our results can inform resource management and enhance our understanding of vegetation vulnerability to climate change.

scholarly journals Large‐scale forest restoration stabilizes carbon under climate change in Southwest United States

2019 ◽  
Vol 29 (8) ◽  
Author(s):  
Lisa A. McCauley ◽  
Marcos D. Robles ◽  
Travis Woolley ◽  
Robert M. Marshall ◽  
Alec Kretchun ◽  
...  
Keyword(s):  
Climate Change ◽  
United States ◽  
Forest Restoration ◽  
Large Scale ◽  
Southwest United States

scholarly journals Contributions of Vegetation Greening and Climate Change to Evapotranspiration Trend after Large-Scale Vegetation Restoration on the Loess Plateau, China

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1755
Author(s):  
Shuo Wang ◽  
Chenfeng Cui ◽  
Qin Dai
Keyword(s):  
Climate Change ◽  
Loess Plateau ◽  
Large Scale ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Potential Evapotranspiration ◽  
Development Trend ◽  
Future Trend ◽  
Natural Ecosystem ◽  
The Loess Plateau

Since the early 2000s, the vegetation cover of the Loess Plateau (LP) has increased significantly, which has been fully recorded. However, the effects on relevant eco-hydrological processes are still unclear. Here, we made an investigation on the changes of actual evapotranspiration (ETa) during 2000–2018 and connected them with vegetation greening and climate change in the LP, based on the remote sensing data with correlation and attribution analysis. Results identified that the average annual ETa on the LP exhibited an obvious increasing trend with the value of 9.11 mm yr−1, and the annual ETa trend was dominated by the changes of ETa in the third quarter (July, August, and September). The future trend of ETa was predicted by the Hurst exponent. Partial correlation analysis indicated that annual ETa variations in 87.8% regions of the LP were controlled by vegetation greening. Multiple regression analysis suggested that the relative contributions of potential evapotranspiration (ETp), precipitation, and normalized difference vegetation index (NDVI), to the trend of ETa were 5.7%, −26.3%, and 61.4%, separately. Vegetation greening has a close relationship with the Grain for Green (GFG) project and acts as an essential driver for the long-term development trend of water consumption on the LP. In this research, the potential conflicts of water demanding between the natural ecosystem and social-economic system in the LP were highlighted, which were caused by the fast vegetation expansion.

scholarly journals Towards Vine Water Status Monitoring on a Large Scale Using Sentinel-2 Images

2021 ◽  
Vol 13 (9) ◽  
pp. 1837
Author(s):  
Eve Laroche-Pinel ◽  
Sylvie Duthoit ◽  
Mohanad Albughdadi ◽  
Anne D. Costard ◽  
Jacques Rousseau ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Potential ◽  
Large Scale ◽  
Water Status ◽  
Vegetation Indices ◽  
Machine Learning Algorithms ◽  
Severe Drought ◽  
Stem Water Potential ◽  
Stem Water ◽  
Sentinel 2

Wine growing needs to adapt to confront climate change. In fact, the lack of water becomes more and more important in many regions. Whereas vineyards have been located in dry areas for decades, so they need special resilient varieties and/or a sufficient water supply at key development stages in case of severe drought. With climate change and the decrease of water availability, some vineyard regions face difficulties because of unsuitable variety, wrong vine management or due to the limited water access. Decision support tools are therefore required to optimize water use or to adapt agronomic practices. This study aimed at monitoring vine water status at a large scale with Sentinel-2 images. The goal was to provide a solution that would give spatialized and temporal information throughout the season on the water status of the vines. For this purpose, thirty six plots were monitored in total over three years (2018, 2019 and 2020). Vine water status was measured with stem water potential in field measurements from pea size to ripening stage. Simultaneously Sentinel-2 images were downloaded and processed to extract band reflectance values and compute vegetation indices. In our study, we tested five supervised regression machine learning algorithms to find possible relationships between stem water potential and data acquired from Sentinel-2 images (bands reflectance values and vegetation indices). Regression model using Red, NIR, Red-Edge and SWIR bands gave promising result to predict stem water potential (R2=0.40, RMSE=0.26).

Can we improve soil properties and plant biomass using rock powder as soil amendment?

2021 ◽  
Author(s):  
Lena Reifschneider ◽  
Vinzenz Franz Eichinger ◽  
Evelin Pihlap ◽  
Noelia Garcia-Franco ◽  
Anna Kühnel ◽  
...  
Keyword(s):  
Climate Change ◽  
Plant Growth ◽  
Large Scale ◽  
Plant Biomass ◽  
New Mineral ◽  
Severe Drought ◽  
Rock Powder ◽  
Overburden Material ◽  
Neutral Soil ◽  
Mitigate Climate Change

<p>The application of rock powder is an option to improve soil fertility while valorising the overburden material produced by industries. The “enhanced weathering” of silicate rock has also gained recent interest in the scientific community for its potential to mitigate climate change. However, the effect of rock powder on the soil physical properties remains unclear, especially under climate change (e.g., increasing drought events). Prior to any large scale application of rock powder, it is crucial to disentangle the potential effects of rock powder application on its environment. In a mesocosm experiment, we explored the effect of three rock powders on plant biomass, soil aggregation and organic carbon (OC) allocation within aggregates, in two soils with clayey and sandy textures, under regular watering or severe drought conditions. We demonstrate that the rock powder was the third factor after drought and soil texture significantly affecting the plant growth, resulting in a significant plant biomass decrease ranging from - 13 % to - 42 % compared with the control. We mainly attribute this effect to the increase of the already neutral soil pH, along with the release of excessive heavy metal amounts at a toxic range for the plant. Yet, we found that adding rock powder to the soil resulted in an increase of the relative amount of microaggregates in the soil by up to + 70 %, along with a re-distribution of OC within the fine fractions of the soil (up to + 32 % of OC in < 250 µm fractions). The new mineral-mineral and organo-mineral interactions promoted by the rock powder addition could potentially favour OC persistence in soil on the long term. With our results, we insist on the potential risks for plant growth associated to the application of rock powder when not handled properly. In addition to the current enthusiasm around the capacity of rock powder to enhance carbon sequestration in the inorganic form, we also encourage scientists to focus their research on its effect on soil structure properties and OC storage.</p>

scholarly journals Interdecadal Seesaw of Precipitation Variability between North China and the Southwest United States

2019 ◽  
Vol 32 (10) ◽  
pp. 2951-2968 ◽  
Author(s):  
Qing Yang ◽  
Zhuguo Ma ◽  
Peili Wu ◽  
Nicholas P. Klingaman ◽  
Lixia Zhang
Keyword(s):  
United States ◽  
North Pacific ◽  
Large Scale ◽  
North China ◽  
Atlantic Multidecadal Oscillation ◽  
Precipitation Variability ◽  
Circulation Anomaly ◽  
Potential Predictability ◽  
Southwest United States ◽  
Rainfall Anomalies

Abstract This paper reports a consistent seesaw relationship between interdecadal precipitation variability over North China and the Southwest United States, which can be found in observations and simulations with several models. Idealized model simulations suggest the seesaw could be mainly driven by the interdecadal Pacific oscillation (IPO), through a large-scale circulation anomaly occupying the entire northern North Pacific, while the Atlantic multidecadal oscillation (AMO) contributes oppositely and less. Modulation of precipitation by the IPO tends to be intensified when the AMO is in the opposite phase, but weakened when the AMO is in the same phase. The warm IPO phase is associated with an anomalous cyclone over the northern North Pacific; consequently, anomalous southwesterly winds bring more moisture and rainfall to the Southwest United States, while northwesterly wind anomalies prevail over North China with negative rainfall anomalies. The east–west seesaw of rainfall anomalies reverses sign when the circulation anomaly becomes anticyclonic during the cold IPO phase. The IPO-related tropical SST anomalies affect the meridional temperature gradient over the North Pacific and adjacent regions and the mean meridional circulation. In the northern North Pacific, the atmospheric response to IPO forcing imposes an equivalent barotropic structure throughout the troposphere. An important implication from this study is the potential predictability of drought-related water stresses over these arid and semiarid regions, with the progress of our understanding and prediction of the IPO and AMO.

scholarly journals Tidal wetland resilience to sea level rise increases their carbon sequestration capacity in United States

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Faming Wang ◽  
Xiaoliang Lu ◽  
Christian J. Sanders ◽  
Jianwu Tang
Keyword(s):  
Climate Change ◽  
United States ◽  
Sea Level Rise ◽  
Sea Level ◽  
Large Scale ◽  
Accumulation Rate ◽  
C Sequestration ◽  
Tidal Wetlands ◽  
Tidal Wetland ◽  
Climate Change Scenarios

AbstractCoastal wetlands are large reservoirs of soil carbon (C). However, the annual C accumulation rates contributing to the C storage in these systems have yet to be spatially estimated on a large scale. We synthesized C accumulation rate (CAR) in tidal wetlands of the conterminous United States (US), upscaled the CAR to national scale, and predicted trends based on climate change scenarios. Here, we show that the mean CAR is 161.8 ± 6 g Cm−2 yr−1, and the conterminous US tidal wetlands sequestrate 4.2–5.0 Tg C yr−1. Relative sea level rise (RSLR) largely regulates the CAR. The tidal wetland CAR is projected to increase in this century and continue their C sequestration capacity in all climate change scenarios, suggesting a strong resilience to sea level rise. These results serve as a baseline assessment of C accumulation in tidal wetlands of US, and indicate a significant C sink throughout this century.

scholarly journals NDVI-Based Vegetation Change in Inner Mongolia from 1982 to 2006 and Its Relationship to Climate at the Biome Scale

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Linghui Guo ◽  
Shaohong Wu ◽  
Dongsheng Zhao ◽  
Yunhe Yin ◽  
Guoyong Leng ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
Inner Mongolia ◽  
Vegetation Change ◽  
Vegetation Index ◽  
Potential Evapotranspiration ◽  
Vegetation Type ◽  
Growing Season ◽  
Desert Steppe

Based on the normalized difference vegetation index (NDVI), we analyzed vegetation change of the six major biomes across Inner Mongolia at the growing season and the monthly timescales and estimated their responses to climate change between 1982 and 2006. To reduce disturbance associated with land use change, those pixels affected by land use change from the 1980s to 2000s were excluded. At the growing season scale, the NDVI increased weakly in the natural ecosystems, but strongly in cropland. Interannual variations in the growing season NDVI for forest was positively linked with potential evapotranspiration and temperature, but negatively correlated with precipitation. In contrast, it was positively correlated with precipitation, but negatively related to potential evapotranspiration for other natural biomes, particularly for desert steppe. Although monthly NDVI trends were characterized as heterogeneous, corresponding to monthly variations in climate change among biome types, warming-related NDVI at the beginning of the growing season was the main contributor to the NDVI increase during the growing season for forest, meadow steppe, and typical steppe, but it constrained the NDVI increase for desert steppe, desert, and crop. Significant one-month lagged correlations between monthly NDVI and climate variables were found, but the correlation characteristics varied greatly depending on vegetation type.

scholarly journals Towards understanding hydroclimatic change in Victoria, Australia – why was the last decade so dry?

2009 ◽  
Vol 6 (5) ◽  
pp. 6181-6206 ◽  
Author(s):  
A. S. Kiem ◽  
D. C. Verdon-Kidd
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Large Scale ◽  
Regional Scale ◽  
Seasonal Rainfall ◽  
Severe Drought ◽  
Physical Mechanisms ◽  
Drought Conditions ◽  
Hydroclimatic Change ◽  
Impacts Of Climate Change

Abstract. Since the mid-1990s Victoria, located in southeast Australia, has experienced severe drought conditions characterized by streamflow that is the lowest on record in many areas. While severe decreases in annual and seasonal rainfall totals have also been observed, this alone does not seem to explain the observed reduction in flow. In this study, we investigate the large-scale climate drivers for Victoria and demonstrate how these modulate the regional scale synoptic patterns, which in turn alter the way seasonal rainfall totals are compiled and the amount of runoff per unit rainfall that is produced. The hydrological implications are significant and illustrate the need for robust hydrological modelling, which takes into account insights into physical mechanisms that drive regional hydroclimatology, in order to properly understand and quantify the impacts of climate change (natural and/or anthropogenic) on water resources.

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